bigger thumbnails in the carousel editor

48px to 96px. At 48 a photograph is a colour swatch — you can tell two apart
but not what either is, which is the one thing the list is for.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

web/sections/CarouselItems.tsx

@@ -154,7 +154,7 @@ export const CarouselItems = ({ carouselId, onChanged }: { carouselId: number; o
               src={thumbUrl(item.url)}
               alt=""
               loading="lazy"
-              className="size-12 shrink-0 rounded bg-muted object-cover"
+              className="size-24 shrink-0 rounded bg-muted object-cover"
               // A file whose conversion has not run has no rung. Hidden rather than left as a broken
               // glyph, which reads as a corrupt picture rather than a pending one.
               onError={(event) => {